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Our future, our universe, and other weighty topics

Thursday, June 19, 2014

The Professor's Cosmic Confusions

There was an interview in the New York
Times a few days ago with Tim Maudlin. The topic was the relation between
religious ideas and modern cosmology. Since Maudlin is a professor of
philosophy at New York University, and the author of a book on the
philosophy of physics, readers might have expected some keen
insights, but what they got instead was very shaky reasoning.

Maudlin spends the first part of the
interview trying to suggest that cosmology has discredited
religious thinking because it shows that the universe is very big,
that man is not the center of the universe, and that the universe was
not created specifically for the human species. Maudlin asserts, “Theism,
as religious people typically hold it, does not merely state that
some entity created the universe, but that the universe was created
specifically with humans in mind as the most important part of
creation.“ This is what is
called a straw man argument, an attempt to discredit something by
presenting some ridiculous caricature of it. Not many serious
astronomically-literate thinkers of the past fifty years have
maintained that our vast universe was created mainly for the sake of
the human species, or that man is the most important species in the universe.
Theism may simply be defined as the belief that some higher power
created the universe. The outdated belief that man is the most
important part of the universe is an entirely separate belief that is not at all a consequence of theism. Discrediting that outdated
belief does absolutely nothing to discredit theism.

The interviewer then mentions that
some have argued that the universe's fundamental constants seem to be
fine-tuned (as discussed here), and that may suggest that the universe was designed by
some intelligence interested in having intelligent creatures exist.
Here is Maudlin's reply:

Our physical theories contain
quite a large number of “constants of nature,” of which we have
no deeper account. There seem to be more of them than most physicists
are comfortable with, and we don’t know for sure whether these
“constants” are really constant rather than variable. This gives
rise to questions about “fine-tuning” of these constants. One
thing to keep in mind is that the true number and status of the
“constants of nature” is not part of any well-established
physical theory: It is part of what we don’t yet know rather than
what we do know...Since we don’t even know if the “constants”
are constant, we certainly don’t know enough to draw any
conclusions about the best account of why they have the particular
values they have right now and around here. Since we don’t know how
the various “constants” might be related to each other by deeper
physics, the game of trying to figure out the effect of changing just
one and leaving the rest alone also is not well founded.

These statements are a combination of
misinformed falsehoods and irrelevancies. Very far from being “part
of what we don't yet know rather than what we do know,” the
fundamental constants are some of the more well-understood aspects of
nature. We pretty much know everything about them except why they
have the numerical values that they have. We know the fundamental constants of
nature (things such as the gravitational constant, the proton charge,
the proton mass, and the speed of light) so well that we have
measured their values to six decimal places or more, as shown in the table below. Maudlin's claim
that the constants of nature are “not part of any well-established
physical theory” is hilarious. The constants of nature are, in
fact, fundamental parts of the most well-established theories in
modern science: Einstein's theory of special relativity, Einstein's
theory of general relativity, quantum mechanics, and the Standard
Model of Physics. We also know with a very high likelihood that the
constants of nature have varied by almost no amount over the course
of billions of years. Studies of quasars and isotopes typically
produce a result such as a variation of less than 1 part in 100,000
over a billion years. Whether they vary by a very tiny amount over
billions of years is irrelevant to discussions of whether such
fine-tuned constants support the idea that the universe was
purposefully created.

“Trying to figure out the effect of
changing just one [constant] and leaving the rest alone” is not a
game, but a perfectly serious scientific task which quite a few
scientists have engaged in over the past five decades, publishing
their results in scientific papers (100 examples can be found here).
Far from being “not well founded,” such results are numerically
rigorous and as well-founded as any other scientific results. In
short, almost everything Maudlin says on this topic is off-base.

Fundamental physical constants

Maudlin also reasons as follows:

One thing is for sure: If there
were some deity who desired that we know of its existence, there
would be simple, clear ways to convey that information. I would say
that any theistic argument that starts with the constants of nature
cannot end with a deity who is interested in us knowing of its
existence.

This argument is
irrelevant because whether a creator wants us to know of his
existence is a separate issue from whether such a creator exists. It
is entirely possible that there exists a creator who is not
particularly interested in whether tiny small-brained bit-player
creatures such as us are certain of that creator's existence at this
point in our development. A theist could also argue that the creator
has left signs of his work in nature (the Big Bang, the exact
equality of the proton charge and electron charge, the extreme fine-tuning
of the cosmological constant, the improbable smoothness of the
universe, and so forth), and that the gradual unveiling of such signs
over decades (with the help of science) is ultimately more uplifting
than some one-shot affair of seeing something like a “God exists”
sign in the sky.

Perhaps
realizing that he has failed to shoot down the idea that the
universe's fine-tuning may suggest a cosmic creator, Maudlin then
resorts to the favorite last resort of the champions of blind chance:
a theory of an infinity (or near-infinity) of other universes. When
all else fails, pull a multiverse out of your hat. Maudlin concedes
that “this idea is highly speculative, and there is
no direct evidence in its favor. “ One might also add that
postulating an infinity of universes fails
from the standpoint of Occam's Razor (“entities should not be
multiplied beyond necessity”), because it leads you to the most
complicated explanation possible rather than the simplest
explanation. Moreover, a multiverse fails as an explanation because
it postulates a situation in which there may be a likelihood of some
universe being habitable, but does not change the odds of our
universe being habitable, which are exactly the same regardless of
whether a multiverse exists. There is also the fact that while we
know many things are due to coincidence and we know that many things
are due to design, in the history of explanation there is not one
verified case of anything being successfully explained by assuming a
multiverse; so in that sense a multiverse explanation is not on solid
intellectual ground. We may also wonder: if Maudlin doesn't think the fine-tuning of physical constants is such a big deal (as he suggests), then why he is going to the extreme of suggesting a vast number of universes to try to explain it?

Discussing whether
the Big Bang (the sudden origin of the universe about 13 billion
years ago) may support the idea that the universe had a creator,
Maudlin says, “I think we don’t know enough to make any plausible
guess about even whether there was an initial state, much less what
it might have been. This goes beyond what we have good evidence or
theory for.” Most cosmologists would disagree with that statement.
Such scientists say that we do have good evidence that the universe
suddenly began about 13 billion years ago in the event called the Big
Bang. The evidence includes the cosmic background radiation and the
expansion of the universe (“rewinding the tape” on a universe in
which galaxies are all flying farther and farther apart from each other leads inevitably to a point of
sudden origin in a state of incredible density).

Schematic diagram of Big Bang and expanding universe

There is abundant
evidence that something like the Big Bang was the beginning of our
universe, which is why Penzias and Wilson won the Nobel Prize. There
may be some small degree of uncertainty in regard to this beginning,
a little wiggle room for doubt, but it is not accurate to claim as
Maudlin does that “we don’t know enough to make any plausible
guess about even whether there was an initial state.” We do have
enough not just to make a plausible guess, but to make a
high-probability conclusion: the evidence very clearly indicates us
that there very probably was a sudden beginning 13 billion years
ago. It also indicates that the initial physical state of the
universe had "an enormous amount of fine-tuning," in the words of a recent scientific paper on the topic, discussed here.

Maudlin also
states, “As yet, there is no direct experimental evidence of a
deity, and in order for the postulation of a deity to play an
explanatory role there would have to be a lot of detail about how it
would act.” But, in fact, modern scientists do grant an explanatory
role for things for which there is no direct experimental evidence,
even when they don't have any details about such things or how they
act. Two such things are dark matter and dark energy, both of which
are completely mysterious, not understood in any detail, and not
things that have been confirmed by any experiment. Scientists are
willing to adopt completely vague ideas of the likely existence of
dark matter and dark energy, without any details, because they find
postulating such things useful in explaining certain hard-to-explain
characteristics of our universe. So by requiring a “lot of detail”
about an explanatory factor before making an explanatory assumption,
Maudlin is setting up some artificially high hurdle for the
hypothesis of a divine creator, one that scientific assumptions are
not required to meet.

Postscript: A huge team of scientists (the Planck satellite team) has just released a paper finding that two of the fundamental constants of nature (the fine structure constant and the electron mass) have changed by less than 1 percent since the beginning of the universe.

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All posts on this blog are authored by Mark Mahin, and are protected by copyright. Copyright 2013-2014 by Mark Mahin. All rights reserved. Any resemblance between any fictional character and any real person is purely coincidental.